Planning poker is an agile technique for estimating the work effort of the product backlog Items. The method originally comes from the XP process but is now used in many agile and non-agile methodologies. Basically it works like this:
1. Each team member (some include the Product Owner, others do not) is given a deck of Planning Poker cards. A typical deck has cards based a modified Fibonacci sequence with values of 0, 1, 2, 3, 5, 8, 13, 20, 40, 100. The reason for using the Fibonacci-like sequence is to reflect the inherent uncertainty of estimating larger items. The values relate to or generally represent the story points, days or some other unit.
2. The project manager, business analyst, or product owner reads the user story.
3. The team discusses the item and ask questions to sufficiently understand the requirements just to the degree necessary to make their estimate.
4. Each estimator privately selects a card that they feel represents the effort that will be sufficient (on average) to complete the item to the team’s definition of done.
5. Once everyone has estimated, they each turn their cards face up at the same time. The persons who provided the highest and lowest estimates are asked to share their reasoning. After a discussion which may involve further explanation, examples, or references, everyone reselects a card and they are all, once again, revealed together.
6. This estimation process is repeated for each item until a consensus is reached (or a decision is made to defer the estimation until more clarification or information can be obtained.)
Planning poker sessions may be held a various points. Usually they are held once the product backlog has been initially formulated. Sessions may also be held earlier (at the feasibility or foundation phase, or the portfolio/program level) for epic user stories. And subsequent sessions may also be held during an iteration to address added or modified stories.